Starter for internal-combustion engine

ABSTRACT

In Bendix-type starters, the stop disc has bent portions axially extending perpendicularly to its plane on the periphery of its concentric opening and is attached to the holder for the pinion by having the pinion&#39;&#39;s sleeve snugly fitted into the opening. The pinion and sleeve include the respective helical splines provided with lopped ends adapted to abut against the free edges of the bent portions on the disc. This prevents the pinion from striking against its holder ensuring that the engine is always started.

United States Patent lnventors Tsuyoshi Matsumoto;

Yoshio Kusajima, both of Himeji, Japan Appl. No. 4,832 Filed Jan. 22,1970 Patented Dec. 28, 1971 Assignee Mitsubishi Denki Kabushiki KaishaTokyo, Japan Priority Jan. 23, 1969 Japan 44/5915 STARTER FORINTERNAL-COMBUSTION ENGINE 7 Claims, 5 Drawing Figs. 9

U.S. Cl 74/7 Int. Cl F02n 11/00 Field of Search 7417 R, 7 B,

[56] References Cited UNITED STATES PATENTS 2,907,216 10/1959 Smith 74 72,944,427 7/1960 Antonidasetal 74 7 Primary Examiner-Milton KaufmanAttorneys-Robert E. Burns and Emmanuel J. Lobato ABSTRACT: InBendix-type starters, the stop disc has bent portions axially extendingperpendicularly to its plane on the periphery of its concentric openingand is attached to the holder for the pinion by having the pinionssleeve snugly fitted into the opening The pinion and sleeve include therespective helical splines provided with lopped ends adapted to abutagainst the free edges of the bent portions on the disc. This preventsthe pinion from striking against its holder ensuring that the engine isalways started.

PATENTEnuficzml 316230.092

I PRIOR ART 34 32 3028 Z9 FIG? STARTER FOR INTERNAL-COMBUSTION ENGINEBACKGROUND OF THE INVENTION This invention relates to improvements inBendix type of starting devices for use with internal-combustion engineswhereby the pinion is adapted to slide into meshing engagement with theassociated ring gear for the engine by means of its own inertia.

The earlier Bendix type of starter devices referred to wasdisadvantageous in that upon rotating the engine by itself, thereenergization of a starting motor involved through any erroneousoperation caused the pinion to push against and stick to the associatedholder thereby to restrain the pinion from axially moving and thereforedisable the engine from starting. Although there have been previouslyproposed various attempts to eliminate that disadvantage they have stillexhibited objections to operation. Alternatively they have beendifficult to be manufactured.

SUMMARY OF THE INVENTION An object of the invention is to provide a newand improved starter device for use with an internal-combustion engineeffective for preventing a pinion involved from sticking to theassociated holder ensuring that the engine is started whenever it isnecessary to do so.

The invention accomplished this object by the provision of a startingdevice for use with an internal-combustion engine, comprising, incombination, a shaft put in rotation upon starting the engine, a ringgear for the engine a pinion fitted onto the shaft through a helicalspline sleeve and opposing to the ring gear, a buffer member for dampingthe movement of the pinion toward that side thereof remote from the ringgear, a holder plate disposed on the shaft between the buffer member andthe pinion, and a stopper formed of a member different from the splinesleeve to prevent the pinion from abutting against the holder plate.

BRIEF DESCRIPTION OF THE DRAWING The invention will become more readilyapparent from the following detailed description taken in conjunctionwith the accompanying drawing in which:

FIG. 1 is a side elevational view, partly in longitudinal section of astarting device for an internal-combustion engine constructed inaccordance with the principles of the prior art;

FIG. 2 is side elevational view, partly in longitudinal section of astarting device for an internal-combustion engine constructed inaccordance with the principles of the invention;

FIG. 3 is a perspective view of the screw-threaded sleeve shown in FIG.2;

FIG. 4 is a perspective sectional view of the pinion shown in FIG. 2;and

FIG. 5 is a perspective view of the screw stopper for the pinion shownin FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing andparticularly to FIG. 1 there is illustrated a starting device of theBendix type for use with an internal-combustion engine constructed inaccordance with the principles of the prior art. The arrangementillustrated comprises an output shaft connectable to a starting electricmotor (not shown) having a plurality of straight splines 12 disposed onthe outer surface of one portion thereof, and a screw-threaded sleevegenerally designated by the reference numeral 14 and having a pluralityof straight splines 16 disposed on the inner peripheral surface thereofto be engaged by the straight splines 12 on the shaft I0 and a pluralityof helical splines 18 disposed on the outer peripheral surface thereof.Then a pinion generally designated by the reference numeral 20 is put inspline fit with the sleeve 14 by having a plurality of helical splines22 disposed on the inner peripheral surface thereof and engaged by thehelical splines I8 on the sleeve 14. The output shaft 10 is shown inFIG. 1 as having a helical return spring 24 disposed around the samebetween the sleeve 14 and a stopper 26 fixedly secured to the free endportion thereof to serve to stop the pinion 20.

As shown in FIG. I, the pinion 20 includes an end face remote from thestopper 26 and normally abutting against a holder disc 28 in the form ofa thrust washer mounted on the shaft 10 and contacting a cup-shapedcover 30 also mounted on the shaft 10. An annular buffer member orcushioning means 32 made of rubber is disposed in contact relationshipwithin the cup-shaped cover 30 and supported at the free end by asupport disc 34 rigidly secured on the shaft 10. FIG. 1 also shows oneportion of a ring gear 36 for the engine (not shown) below the sleeve14.

The arrangement illustrated is operated as follows: Upon starting theengine (not shown), the starting motor (also not shown) is energized toacceleratedly rotate the output shaft 10 thereof. This rotationalmovement of the shaft 10 causes the pinion 20 to be moved from itsinitial starting position in the right-hand direction as viewed in FIG.1 along the sleeve 14 due to its own inertia until it meshes with thering gear 36. This movement to the right is accomplished by the factthat when the shaft 10 is initially rotated, the pinion 20, because ofits inertia, will not immediately rotate with the shaft but instead willbe axially translated along the shaft 10 towards the ring gear 36.

At the instant the pinion 20 meshes with the stationary ring gear 36,the rotational motion of the shaft 10 is imparted to the pinion 20causing same to accordingly rotate. On the other hand, as soon as thepinion 20 engages with the ring gear 36 and starts to rotate against thestationary ring gear, the latter momentarily exerts a repelling force onthe pinion 20 opposing the rotational movement of the pinion. Thisrepelling force or shock is transmitted through the helical splines 22and 18, the thrust washer 28 and the cover 30 to the resilient buffermember 32 which, due to its resilience, effectively absorbs this shockenergy.

Then the ring gear 36 until it is returned back to its original positionas illustrated in FIG. I in readiness for the succeeding operation.

However the arrangement has several disadvantages which will besubsequently described.

It is now assumed that during the operation of starting the engine, thereenergization of the starting motor is erroneously effected after theengine has reached the self-rotating state. Under the assumed conditionthe pinion 20 abuts against the ring gear 36 whereupon the pinion 20 isimmediately repelled by the ring gear 36 to be moved in the left-handdirection as viewed in FIG. 1 along the sleeve 14 until it strikesagainst the thrust washer 28. This causes the pinion 20 to push againstthe washer 28 with a force sufficient to stick the pinion to the washer.Therefore the subsequent energization of the starting motor causes thepinion 20 to be rotated together with the sleeve 14 without the axialmovement effected resulting in the occurrence of a failure that theengine is unable to be started.

In order to avoid this failure, it has been previously considered toincrease the lead angle for each of the helical splines 18 and 22 (whichgenerally ranges from 20 to 30) to thereby alleviate the impact of thepinion 20 on the washer 28. This measure has caused the thrust force formeshing the pinion 20 with the ring gear 36 to be insufficient with theresult that the pinion 20 does not always mesh with the ring gear 36.Alternatively, the pinion 20 might have a pulsating torque appliedthereto by the ring gear 36 during start of the engine leading to thedisengage of the pinion from the ring gear.

Also the above-mentioned disadvantage may be eliminated by terminatingthe helical splines 18 suitably short of the side of the washer 28without the splines running throughout the length for the purpose ofrestraining the pinion 20 from abutting against the washer 28. In thatevent the helical splines 18 can not be machined through the hobbingoperation and the splines are required to be machined by reciprocatingthe associated single cutting edge tool along the sleeve 14 as manytimes as the number of the splines 18 resulting in a great reduction inproductivity. Furthermore a particular single cutting edge toolrelatively small in diameter is necessarily used in order satisfactorilyto machine the splines in the manner as above described.

The invention contemplates to eliminate the above-mentioneddisadvantages of and objections to the prior art practice.

Referring now to FIG. 2 wherein like reference numerals designate thecomponents corresponding or similar to those shown in FIG. 1, there isillustrated a starting device for an internal-combustion engineconstructed in accordance with the principles of the invention. Only theimprovements made by the invention will now be described with referenceto FIGS. 2 through 5.

As best shown in FIG. 3, the screw-threaded sleeve 14 is provided on theouter peripheral surface with a plurality of helical splines 18 and onthe inner peripheral surface with a plurality of straight splines 16 asdoes the sleeve 14 shown in FIG. 1. It is, however, to be noted thatthose helical spline portions adjacent to the washer 28 of the sleeve 14are lopped or trimmed ofi at 182 to form a plain annulus 184 between theedge of the sleeve 14 and the lopped ends 182 of the splines 18, for thepurpose as will be apparent hereinafter.

Thepinion 20 is similar in construction to the pinion 20 shown in FIG. 1excepting that the helical splines 22 disposed on the inner peripheralsurface thereof terminate at lopped or trimmed ends 222 formed at theend adjacent the washer 28 of the pinion 20.

As shown in FIG. 2, a position-limiting member comprising a disc-shapedscrew stopper generally designated by the reference numeral 40 isrigidly secured to the exposed face of the thrust washer 28 andconcentric with the shaft 10. As shown in FIG. 5, the screw stopper 40includes a disc 402 of any suitable metallic material such as iron, anda plurality of, in this case, three bent portions or projections 404disposed at substantially equal angular intervals on a circle having thesame center as the disc 402 with the circle defining an opening 406concentric with the disc 402. The bent portions 404 extend substantiallyperpendicularly to the plane of the disc 402 or axially thereof suchthat each bent portion merges into the plane of the disc at one end andprogressively increases in height toward the other end thereof until itterminates in an axially directed edge 408 at the other end. Thus theextremity of the bent portion 404 forms a tilted or inclined edge 410.

The screw stopper as above described is preferably manufactured bypunching and pressing a relatively thick piece of sheet iron.

When attached on the left-hand face as viewed in FIG. 2 to the washer28, the screw stopper 40 has the circular opening 406 into which theplain annulus 184 is snugly fitted, the axial edges 408 abutting againstthe corresponding lopped ends 182 of the helical sleeve splines 18, andthe tilted or inclined edges 410 abutting against the corresponding wallfaces of the helical sleeve splines 18.

In operation, it is assumed that the pinion 20 has been applied with athrust tending to move it in the left-hand direction as viewed in FIG. 2as in the arrangement of FIG. 1. Then the lopped ends 222 of the pinionsplines 22 directly abut against the axial edges 408 on the screwstopper 40 until the pinion 20 is stopped in its initial position whilea gap having a distance I is left between the adjacent faces of thepinion 20 and the stopper 40 as shown in FIG. 2. This gap is effectivefor preventing the pinion 20 from striking against the washer 28,thereby to fully eliminate the failure that upon rotating the engine byitself, reenergization of thestarting motor through any erroneousoperation causes the pinion 20 to push against and stick to the washer28 leading to the prevention of the axial movement of the pinion andhence the engine being disabled to be started.

If, due to the repeated impacts of the lopped ends 222 against the axialedges 408 the mechanical strength of those edges 408 come in question,then the entire screw stopper 40 may be subjected to a surface hardeningtreatment. Alternatively it may be suitably increased in thickness.

From the foregoing it will be appreciated that the object of theinvention has been accomplished by the provision of the screw stopperserving to prevent the pinion from sticking to the holder such as thethrust washer.

While the invention has been illustrated and described in conjunctionwith a single preferred embodiment thereof it is to be understood thatvarious changes in the details of construction and the arrangement andcombination of parts may be resorted to without departing from thespirit and scope of the invention. For example, the washer 28 may beintegral with the screw stopper 40. Alternatively the screw stopper 40may be attached to the sleeve 14 rather than to the washer 28.

What we claim is:

l. A starting device engageable with a ring gear of aninternal-combustion engine for starting same, comprising: a rotatableshaft, a pinion splined onto said shaft through a helically splinedsleeve and having means thereon engageable with said ring gear, a buffermember for damping the movement of the pinion toward that side thereofremote from the ring gear, a holder plate disposed on said shaft betweensaid buffer member and said pinion, and a screw stopper composed of asheet material and attached to said holder plate effective to preventsaid pinion from abutting against said holder plate.

2. A starting device as claimed in claim I wherein said stopper isdisposed between said holder plate and said pinion and includes a disc,a plurality of bent portions bent substantially perpendicularly to theplane of the disc in the axial direction of the disc, and a tilted edgeand an axial edge disposed on each of said bent portions, said tiltededge being capable of abutting against a helical spline disposed on saidsleeve, said axial edge preventing said pinion from abutting againstsaid holder plate.

3. A starting device as claimed in claim 1 wherein said stopper isdisposed between said holder plate and said pinion and includes a disc,a plurality of bent portions bent substantially perpendicularly to theplane of the disc in the axial direction of the disc, and a tilted edgeand an axial edge disposed on each of said bent portions and whereinsaid sleeve and said pinion each include a plurality of helical splineshaving lopped ends abutting against said axial edges of said bentportions.

4. In a starting device for imparting starting rotation to a drivenmember; a rotatable input member rotationally driven in a givendirection during use of the starting device; a driving member havingmeans thereon releasably engageable with a driven member to be rotated;means mounting said driving member on said input member fortranslational movement therealong between a first position wherein sameis out of engagement with the driven member and a second positionwherein same both releasably engages with the driven member andconcurrently rotates with said input member to impart starting rotationto the driven member in response to rotation of said input member;cushioning means for cushioning the return movement of said drivingmember to said first position; and a position-limiting member disposedexteriorly around said input member between said cushioning means andsaid driving member directly engageable with said driving member duringmovement thereof to said first position to position same in said firstposition.

5. A starting device according to claim 4; wherein said means mountingsaid driving member on said input member comprises means defininghelical splines on both said driving and input members in splinedengagement with each other; and wherein said position-limiting membercomprises an annular disc mounted on said input member and having aplurality of projections thereon projecting axially towards said drivingmember each of which is positioned to engage with an end portion ofrespective ones of said helical splines on said driving member duringreturn movement thereof to said first position to effectively limitreturn movement of said driving member to said first position.

between said driving member and said thrust washer.

7. A starting device according to claim 5; wherein said driving memberhas sufficient inertia with respect to said input member that initialrotational movement of said input member in said given direction effectstranslational movement therealong of said driving member from said firstposition to said second position.

1. A starting device engageable with a ring gear of aninternalcombustion engine for starting same, comprising: a rotatableshaft, a pinion splined onto said shaft through a helically splinedsleeve and having means thereon engageable with said ring gear, a buffermember for damping the movement of the pinion toward that side thereofremote from the ring gear, a holder plate disposed on said shaft betweensaid buffer member and said pinion, and a screw stopper composed of asheet material and attached to said holder plate effective to preventsaid pinion from abutting against said holder plate.
 2. A startingdevice as claimed in claim 1 wherein said stopper is disposed betweensaid holder plate and said pinion and includes a disc, a plurality ofbent portions bent substantially perpendicularly to the plane of thedisc in the axial direction of the disc, and a tilted edge and an axialedge disposed on each of said bent portions, said tilted edge beingcapable of abutting against a helical spline disposed on said sleeve,said axial edge preventing said pinion from abutting against said holderplate.
 3. A starting device as claimed in claim 1 wherein said stopperis disposed between said holder plate and said pinion and includes adisc, a plurality of bent portions bent substantially perpendicularly tothe plane of the disc in the axial direction of the disc, and a tiltededge and an axial edge disposed on each of said bent portions andwherein said sleeve and said pinion each include a plurality of helicalsplines having lopped ends abutting against said axial edges of saidbent portions.
 4. In a starting device for imparting starting rotationto a driven member; a rotatable input member rotationally driven in agiven direction during use of the starting device; a driving memberhaving means thereon releasably engageable with a driven member to berotated; means mounting said driving member on said input member fortranslational movement therealong between a first position wherein sameis out of engagement with the driven member and a second positionwherein same both releasably engages with the driven member andconcurrently rotates with said input member to impart starting rotationto the driven member in response to rotation of said input member;cushioning means for cushioning the return movement of said drivingmember to said first position; and a position-limiting member disposedexteriorly around said input member between said cushioning means andsaid driving member directly engageable with said driving member duringmovement thereof to said first position to position same in said firstposition.
 5. A starting device according to claim 4; wherein said meansmounting said driving member on said input member comprises meansdefining helical splines on both said driving and input members insplined engagement with each other; and wherein said position-limitingmember comprises an annular disc mounted on said input member and havinga plurality of projections thereon projecting axially towards saiddriving member each of which is positioned to engage with an end portionof respective ones of said helical splines on said driving member duringreturn movement thereof to said first position to effectively limitreturn movement of said driving member to said first position.
 6. Astarting device according to claim 5; further including a thrust washerdisposed around said input member between said cushioning means and saidannular disc; and wherein said helical splines on said driving memberand said projections on said annular disc are sufficiently dimensionedand configured with respect to each other to abut one another duringreturn movement of said driving member thereby positioning same in saidfirst position while preventing direct physical contact between saiddriving member and said thrust washer.
 7. A starting device according toclaim 5; wherein said driving member has sufficient inertia with respectto said input member that initial rotational movement of said inputmember in said given direction effects translational movement therealongof said driving member from said first position to said second position.